title: Influence of long time storage in mineral water on RNA stability of Pseudomonas aeruginosa and Escherichia coli after heat inactivation.
abstract: BACKGROUND
  Research of RNA viability markers was previously studied for many bacterial species. Few and different targets of each species have been checked and motley results can be found in literature. No research has been done about Pseudomonas aeruginosa in this way.
  
  
  RESULTS
  Disappearance of 48 transcripts was analyzed by two-steps reverse transcription and real time polymerase chain reaction (RT-PCR) after heat-killing of Pseudomonas aeruginosa previously stored in mineral water or not. Differential results were obtained for each target. 16S rRNA, 23S rRNA, groEL, and rpmE were showed as the most persistent transcripts and rplP, rplV, rplE and rpsD were showed as the most labile transcripts after P. aeruginosa death. However, the labile targets appeared more persistent in bacteria previously stored in mineral water than freshly cultivated (non stored). These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli. Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli.
  
  
  CONCLUSIONS
  This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts. In a near future, these targets could be associated to develop an efficient viability kit. The present study also suggests that it would be difficult to determine universal RNA viability markers for environmental bacteria, since opposite results were obtained depending on the bacterial species and the physiological conditions.
authors.affiliation: Centre International de Recherche Sur l'Eau et l'Environnement - Suez Environnement, Le Pecq, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Cenciarini
authors.forename: Sophie
authors.initials: S
authors.lastname: Courtois
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
mesh_terms: D015415:Biomarkers; D004926:Escherichia coli / Q000235:genetics*; D020869:Gene Expression Profiling; D006358:Hot Temperature; D050296:Microbial Viability / Q000235:genetics*; D008900:Mineral Waters; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D020871:RNA Stability; D012329:RNA, Bacterial / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D008900:Mineral Waters; D012329:RNA, Bacterial